1. Field of the Invention
The present invention relates to a suspension board with circuit and, more particularly, to a suspension board with circuit on which an electronic component is mounted.
2. Description of Related Art
A suspension board with circuit which is mounted on a hard disk drive typically comprises a metal supporting board, an insulating base layer formed on the metal supporting board, a conductive pattern formed on the insulating base layer, and an insulating cover layer formed on the insulating base layer to cover the conductive pattern. Such a suspension board with circuit is widely used in various electric and electronic equipment.
To prevent diffusion (ion migration) of copper for forming a copper conductive layer into an insulating cover layer in such a suspension board with circuit and thereby prevent the degradation of the copper conductive layer as well as a short circuit between the copper conductive layers, it has been proposed to form a nickel thin film on a surface of the copper conductive layer by electroless nickel plating, thereby coating and protecting the surface of the copper conductive layer (see, e.g., Japanese Unexamined Patent Publication No. 10-12983).
When an electronic component is mounted on a wired circuit board such as a suspension board with circuit, the electronic component may be occasionally broken down by static electricity in the mounting step.
To prevent this, it has been proposed to form a metal layer on a surface of a base film or a cover film in, e.g., a flexible circuit board by vapor deposition, sputtering, electroless plating, or like method, thereby grounding or reducing static electricity (see, e.g., Japanese Unexamined Patent Publication No. 08-153940).